Safety belt apparatus with an acceleration sensor

Abstract

The invention relates to a safety belt apparatus comprising a belt roller ( 12 ) which is preferably resiliently subjected to a bias force in the belt wind-up direction, which carries a more or less rolled up belt ( 11 ) and which can be blocked against a further drawing out by a tooth blocking mechanism which can be triggered by an acceleration sensor ( 13 ) preferably having a movable mass, such as a ball ( 35 ), which has a position control gear ( 18 ) which is preferably coaxial with the belt roller ( 12 ) and which is rotationally fixedly connected to an auxiliary blocking tooth crown ( 14 ) which is directly stressed by an auxiliary pawl ( 17 ) of the acceleration sensor ( 13 ) and which drives a main pawl ( 16 ) which is rotationally fixedly coupled to the belt roller ( 12 ) into a main blocking tooth crown ( 15 ) which is fixed to the housing when stopped by the auxiliary pawl ( 17 ) and in the presence of a drawing out force at the belt ( 11 ) whereupon the further drawing out of the belt is stopped. The invention consists in that the auxiliary blocking tooth crown ( 14 ) is designed as an inner tooth crown at a secondary gear ( 19 ) which is coupled in a rotationally fixed manner to, in particular which meshes with, the position control gear ( 18 ), preferably coaxially; and in that the acceleration sensor ( 13 ) is arranged in the interior of the auxiliary inner blocking tooth crown ( 14 ) so as to be displaceable at least about an axis ( 20, 21 ) in such a manner that with a corresponding constructional design of the auxiliary pawl ( 17 ) the latter can come into blocking engagement with the inner tooth crown ( 14 ) in any installation position of the acceleration sensor ( 13 ).

What is claimed is:  
     
       1. A safety belt apparatus comprising: 
       a belt roller carrying a safety belt, the roller being biased in a belt wind-up direction and capable of being blocked by a tooth blocking mechanism to prevent the belt from extending away from the roller;  
       an acceleration sensor, having a movable mass, for triggering the tooth blocking mechanism;  
       the tooth blocking mechanism comprising:  
       a position control gear engaged with a secondary gear;  
       wherein the position control gear is positioned co-axially with the belt roller and includes a main blocking tooth crown;  
       wherein an inner side of the secondary gear includes an auxiliary blocking tooth crown;  
       an auxiliary pawl operatively connected to the acceleration sensor so that when a condition requiring locking of the belt is detected by the acceleration sensor the auxiliary pawl moves to enter into a blocking arrangement with the auxiliary blocking tooth crown to thereby prevent the rotation of the secondary gear and the position control gear;  
       a main pawl connected to the belt roller and configured to engage the main blocking tooth crown so that further rotation of the roller is stopped and further extension of the belt away from the roller is stopped when rotation of the position control gear stops.  
     
     
       2. The apparatus of claim  1 , further comprising a transmission positioned to operatively connect the position control gear and the main pawl. 
     
     
       3. The apparatus of claim  1 , wherein the acceleration sensor is positioned in an interior of the auxiliary tooth crown and the secondary gear. 
     
     
       4. The apparatus of claim  3 , wherein the acceleration sensor and the auxiliary pawl are configured so that when the acceleration sensor is positioned away from an axis of rotation of the secondary gear the auxiliary pawl enters into a blocking position with the auxiliary blocking tooth when required. 
     
     
       5. The apparatus of claim  1 , wherein the auxiliary blocking tooth crown includes a plurality of teeth, each tooth having a concavely curved surface that forms part of a sphere, the center of the sphere being positioned on an axis of rotation of the secondary gear. 
     
     
       6. The apparatus of claim  5 , wherein the acceleration sensor is positioned in an interior of the secondary gear and the auxiliary pawl is curved so that when the acceleration sensor is positioned at a location away from the axis of rotation of the secondary gear the auxiliary pawl enters into a blocking position with the auxiliary blocking tooth when required. 
     
     
       7. The apparatus of claim  1 , wherein each of the auxiliary blocking tooth crown and the main blocking tooth crown includes a plurality of teeth, wherein the main blocking tooth crown has a larger number of teeth. 
     
     
       8. The apparatus of claim  7 , wherein the ratio of the number of teeth between the main blocking tooth crown and the auxiliary blocking tooth crown is substantially the same as the ratio of the diameter of position control gear to the diameter of the secondary gear. 
     
     
       9. The apparatus of claim  1 , wherein the auxiliary blocking tooth crown may be rotated relative to the secondary gear. 
     
     
       10. The apparatus of claim  1 , wherein the position control gear and the secondary gear are configured to be disengaged so that the secondary gear can be rotated relative to the position control gear. 
     
     
       11. The apparatus of claim  1 , wherein the position control gear has a diameter of approximately one half a diameter of the position control gear. 
     
     
       12. The apparatus of claim  1 , wherein the position control gear has a diameter of approximately one third a diameter of the position control gear. 
     
     
       13. The apparatus of claim  1 , wherein the position control gear has a diameter of approximately one fourth a diameter of the position control gear. 
     
     
       14. The apparatus of claim  1 , wherein the movable mass is a ball.